Apple has sold 1m units of the iPad in the four weeks since it went on sale in the US, suggesting that demand for the touchscreen tablet computer is higher than anticipated.
However, the company faced criticism from users who complained that the 3G iPad, released at the weekend, was delivering poor video performance over AT&T’s network.
By hitting the 1m sales mark in 28 days, Apple can point to the iPad as one of its most successful product launches.
When the iPhone was released in 2007, it took 74 days for Apple to move 1m units. It sold 300,000 iPads on the first day the device went on sale, April 3.
Steve Jobs, Apple chief executive, said “demand continues to exceed supply’’ and that the company was working to catch up.
Apple said last month it would delay the international roll-out of the iPad as it struggled to keep up with demand. International pre-orders will begin next week.
Before the launch, critics wondered whether users would have room for a third device between a smartphone and a personal computer.
“It’s too early to say for sure, but it’s off to a good start,” said Gene Munster, an analyst with Piper Jaffray. “It looks like this is a category that is going to be around.”
Since its launch, iPad users have downloaded more than 12m apps from the App Store. Developers have created at least 5,000 apps unique to the iPad.
Apple also said customers have downloaded 1.5m eBooks from Apple’s new iBookstore, suggesting that many early users were using their iPads as an e-reader.
The company is positioning the iPad as a direct challenger to Amazon’s Kindle device, the market leader in e-readers. Mr Jobs has pledged that the iPad would “go a little further” than the Kindle.
Amazon does not release sales figures, but analysts estimate there are about 3m Kindles in use.
The rosy debut of the iPad has been marred by complaints from users who say the 3G service, which is provided by AT&T, compromises the quality of video and does not allow some apps to work.
In particular, users have complained that when YouTube is played over the 3G network, the quality is reduced from high definition to a lower-resolution version, and that the ABC Player does not work unless it is connected to Wi-Fi.
The Netflix app, however, was reported to be working on the 3G network.
“It’s annoying for people who went out and bought an iPad and thought they would watch video on the bus ride home,” Mr Munster said. “But I don’t think it’s a deal breaker.”
Apple shares rose $5.36, or 2 per cent, to $266.45 in late New York trade on Monday.